8,811 research outputs found
Cellular glutathione content in the organ of Corti and its role during ototoxicity.
Glutathione (GSH) is the major scavenger of reactive oxygen species (ROS) inside cells. We used live confocal imaging in order to clarify the role of GSH in the biology of the organ of Corti, the sensory epithelium of the cochlea, before, during and after the onset of hearing and in ~1 year old mice. GSH content was measured using monochlorobimane (MCB), a non-fluorescent cell permeant bimane that reacts with GSH, forming a fluorescent adduct through a reaction catalyzed by glutathione-S-transferase. GSH content increased significantly in inner hair cells during maturation in young adult animals, whereas there was no significant change in the outer hair cells. However, the GSH content in inner hair cells was significantly reduced in ~1 year old mice. The GSH content of supporting cells was comparatively stable over these ages. To test whether the GSH content played a significant protective role during ototoxicity, GSH synthesis was inhibited by buthionine sulfoximine (BSO) in organotypic cochlear explant cultures from immature mice. BSO treatment alone, which reduced GSH by 65 and 85% in inner hair cells and outer hair cells respectively, did not cause any significant cell death. Surprisingly, GSH depletion had no significant effect on hair cell survival even during exposure to the ototoxic aminoglycoside neomycin. These data suggest that the involvement of ROS during aminoglycoside-induced hair cell death is less clear than previously thought and requires further investigation
Jet Quenching: the medium modification of the single and double fragmentation functions
The physics of the quenching of hard jets in dense matter is briefly
reviewed. This is presented within the framework of the partonic medium
modification of the fragmentation functions. Modifications in both deeply
inelastic scattering (DIS) off large nuclei and high-energy heavy-ion
collisions are presented.Comment: 4 pages, 4 figures, Proceedings of the First Meeting of the APS
Topical Group on Hadronic Physics, Fermilab, Batavia, Illinois, Oct 24-26,
200
Ethnic populations of India as seen from an evolutionary perspective
It is now widely accepted that (i) modern humans,Homo sapiens sapiens, evolved in Africa, (ii) migrated out of Africa and replaced archaic humans in other parts of the world, and (iii) one of the first waves of out-of-Africa migration came into India. India, therefore, served as a major corridor for dispersal of modern humans. By studying variation at DNA level in contemporary human populations of India, we have provided evidence that mitochondrial DNA haplotypes based on RFLPs are strikingly similar across ethnic groups of India, consistent with the hypothesis that a small number of females entered India during the initial process of the peopling of India. We have also provided evidence that there may have been dispersal of humans from India to southeast Asia. In conjunction with haplotype data, nucleotide sequence data of a hypervariable segment (HVS-1) of the mitochondrial genome indicate that the ancestors of the present austro-asiatic tribal populations may have been the most ancient inhabitants of India. Based on Y-chromosomal RFLP and STRP data, we have also been able to trace footprints of human movements from west and central Asia into India
Indian caste origins: genomic insights and future outlook
This article does not have an abstract
Dissecting the genetics of cardiomyopathy in India: a tale of ten steps
This article does not have an abstract
Resolving the plasma profile via differential single inclusive suppression
The ability of experimental signatures to resolve the spatio-temporal profile
of an expanding quark gluon plasma is studied. In particular, the single
inclusive suppression of high momentum hadrons versus the centrality of a
heavy-ion collision and with respect to the reaction plane in non-central
collisions is critically examined. Calculations are performed in the higher
twist formalism for the modification of the fragmentation functions. Radically
different nuclear geometries are used. The influence of different initial gluon
distributions as well as different temporal evolution scenarios on the single
inclusive suppression of high momentum pions are outlined. It is demonstrated
that the modification versus the reaction plane is quite sensitive to the
initial spatial density. Such sensitivity remains even in the presence of a
strong elliptic flow.Comment: 5 pages, 4 figures, RevTex
Jet modification in three dimensional fluid dynamics at next-to-leading twist
The modification of the single inclusive spectrum of high transverse momentum
() pions emanating from an ultra-relativistic heavy-ion collision is
investigated. The deconfined sector is modelled using a full three dimensional
(3-D) ideal fluid dynamics simulation. Energy loss of high partons and
the ensuing modification of their fragmentation is calculated within
perturbative QCD at next-to-leading twist, where the magnitude of the higher
twist contribution is modulated by the entropy density extracted from the 3-D
fluid dynamics simulation. The nuclear modification factor () for pions
with a GeV as a function of centrality as well as with respect to
the reaction plane is calculated. The magnitude of contributions to the
differential within small angular ranges, from various depths in the
dense matter is extracted from the calculation and demonstrate the correlation
of the length integrated density and the from a given depth. The
significance of the mixed and hadronic phase to the overall magnitude of energy
loss are explored.Comment: 5 pages, 4 figures, Revte
Linkage mapping of quantitative trait loci in humans: an overview
In this article, we provide an overview of the different statistical procedures that have been developed for linkage mapping of quantitative trait loci. We outline the model assumptions, the data requirements and the underlying tests for linkage for the different methods
Baryonic Strangeness and Related Susceptibilities in QCD
The ratios of off-diagonal to diagonal conserved charge susceptibilities
e.g., chi_{BS}/chi_{S}, chi_{QS}/chi_{S}, related to the quark flavor
susceptibilities, have proven to be discerning probes of the flavor carrying
degrees of freedom in hot strongly interacting matter. Various constraining
relations between the different susceptibilities are derived based on the
Gell-Mann-Nishijima formula and the assumption of isospin symmetry. Using
generic models of deconfined matter and results form lattice QCD, it is
demonstrated that the flavor carrying degrees of freedom at a temperature above
1.5T_c are quark-like quasiparticles. A new observable related by isospin
symmetry to C_{BS} = -3chi_{BS}/chi_{S} and equal to it in the baryon free
regime is identified. This new observable, which is blind to neutral and
non-strange particles, carries the potential of being measured in relativistic
heavy-ion collisions.Comment: 12 pages, 5 figures, RevTex
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